We plan to employ solid state high resolution NMR techniques in the examination of single crystal spectra of amino acids, peptides, and one peptide antibiotic, gramacidin-A (GA). Studies of the 13C spectra of amino acid crystals of known structure will allow determination of the principle values and orientations of chemical shift tensors in the molecular frame. This tensor data will in turn be employed in partial determinations of the crystal and molecular structure of crystals of amino acids and small oligopeptides of unknown structure, and it will also be useful for determining order parameters of peptides in membranes. Furthermore, the data can be employed in the interpertation of high resolution liquid spectra of proteins obtained at high fields, and it will allow us to ascertain at what field chemical shift anistropy relaxation will begin to dominate solution linewidths. We also plan to study 14N dipolar splittings in 13C spectra in order to obtain internuclear distances and directions and 14N quadrupole coupling constants. Finally observation of 13C spectra in both the solid and liquid phases should allow detection solid-liquid conformation differences. In addition, we plan to investigate 14N single crystal spectra of amino acids and peptides. These experiments will be performed at 6.8T fields and with proton decoupling, and consequently we will be able to measure nitrogen quadrupole coupling and chemical shift tensors simulatneously. This approach will afford accurate values of quadrupole coupling tensors and will circumvent the problem of detecting weak 15N signals for nitrogen shift tensor measurements. The nitrogen tensor data will be used for the same purposes as the 13C tensor data. Initially we plan to perform this work on six amino acids-Gly, Ala, Leu, Val, Trp, and Pro - and derivatives of these compounds. The first five of these are constituents of GA, and the small oligopeptides which we intend to investigate are composed of the first two plus Pro. Thus, an examination of the single crystal spectra of only six residues will place us in a position to interpret the spectra of the oligopeptides and the peptide antibiotic. In the studies of GA we plan to determine the pitch of its dimeric helix and thus to differentiate between the conformers proposed for this compound. These studies will be useful for understanding the alkali cation permeativity which (Text Truncated -Exceeds Capacity)